Much
It was actually fairly easy. I did most of the shopping the weekend before (except the berries and vegetables) and made the chocolate sauce and the dulce de leche. I made the salsas; alfajores; empanada dough and filling; yerba mate syrup, and ice cream 3 days before. I baked bread, set the table, and arranged the serving platters the day before. I wanted all the kitchen mess stuff done before my housekeeper arrived on Friday.
The day of the party, I made the potato salad in the morning, I grilled mid-afternoon, placed the meat in a large pan, covered with foil, and placed in the oven at 175F to hold. Vegetables I held at room temp. No one got rare steak, but it was all yummy and so tender held for 2 hours that way. I plated the food and covered with plastic wrap and set it out on the buffet a couple hours before company arrived. Then I helped myself to a yerba mate martini and went off to the shower an hour before company arrived.